What material is used for the GTAW electrode?

• A. Iron
• B. Tungsten
• C. Aluminum
• D. Copper

Answer: (B)

GTAW uses a non-consumable electrode, and tungsten is the material chosen for that role because it has an extremely high melting point and resists erosion in the welding arc. This lets the arc stay stable and focused without the electrode melting into the weld or contaminating the pool. Tungsten’s robustness also means it can be used with both AC and DC currents to weld a wide range of metals, with the filler metal providing the actual addition material as needed.

Using iron, aluminum, or copper as the electrode would be impractical because their much lower melting points would cause them to burn away or fuse into the weld, distorting the arc and introducing unwanted material into the weld pool. Tungsten’s properties—high melting point, stability, and inertness with common shielding gases—make it the appropriate electrode for GTAW.